1. Field of the Invention
This invention relates to apparatus for use in exercise of the human body, and in particular, it relates to an improvement in exercise equipment which is in the nature of a barbell.
2. Description of the Prior Art
It is known, for example, from Bailey et al U.S. Pat. No. 3,384,370, to provide an exercise device or weightlifting apparatus which is in the nature of a set of barbells, but has, along the length of the bar which bears the weights near its ends a pair of generally circular housings that contain handle members. From the Bailey et al patent, it can be taken as already known that it is possible to have barbells which may be used in such a manner that, for example, in raising the barbells from the floor to chest level, the hands of the user may be rotated from an initial position (with their palms facing each other) to a second position (with the palms facing the user's chest). It is known to those skilled in the art of body building that this particular motion of rotating the hands is called "supination", and the reverse motion, from palms facing chest to palms facing each other, is called "pronation".
It has been known, before the present invention, that the biceps muscles, located in the upper arm between the elbow and the shoulder, are involved in the action of supination, in addition to performing the task for which they are best known, namely, flexing the arm to bring the hands inwardly toward the body.
Ordinary barbells, ones consisting of an elongated rod and weights thereon near to its ends, though useful for many exercises, do not serve the purpose of providing exercise to the particular muscles which are involved in the process of supinating. With ordinary barbells, ones without the circular housings and handles shown in the above-mentioned Bailey et al patent, there is an absolute minimum of development of the muscles involved in the supinating action. It would not be accurate to say that such use of known barbells of the kind having a simple straight barbell provide no development whatever of the portions of the biceps muscles involved in the action of supinating, because it is impossible to increase appreciably the overall strength of the biceps muscles without obtaining at least some effect of this sort. At the same time, however, the degree of development in the supinating function of the biceps muscles can be achieved using a straight-bar barbell is, relatively speaking, minimal. Those skilled in the art of body building have recognized that to obtain a more nearly optimal development of the biceps muscles, it is necessary to perform some exercises which at least involve some supinating and pronating action, such as the use of either individual dumbbells held in the two hands or the use of a barbell with handles located in circular housings along a barbell, as in the above-mentioned U.S. Pat. No. 3,384,370.
What has been missing from the prior art is an exercise device which includes a means for adjusting, as desired, the degree of resistance to the supinating and pronating actions. In the prior art as exemplified by U.S. Pat. No. 3,384,370, there are provided handles which are capable of being turned, so that supination can be performed while curling the barbell, but in the device of that patent, there are used roller bearings to provide "greater ease of movement, more flexibility and less strain on the wrists and elbow joints of the user."
Moreover, in the prior art, there are known a number of different kinds of barbell which possess, for various different purposes, gripping portions which are variously located farther apart or closer together and/or variously angularly oriented with respect to the main central longitudinal axis of the barbell. The prior art has not suggested how it would be possible, by providing one apparatus equipped with appropriate spacers and connection means and with tension-adjustment means capable of locking the handles in any desired position, to achieve with one apparatus what had previously required the use of a few different kinds of special-purpose barbell.